Fix type parameter defaults

They should not be applied in expression or pattern contexts, unless there are
other explicitly given type args.

4 files changed, 137 insertions, 83 deletions

diff --git a/crates/ra_hir_ty/src/tests/display_source_code.rs b/crates/ra_hir_ty/src/tests/display_source_code.rs
index 4088b1d22..5dfa0a014 100644
--- a/crates/ra_hir_ty/src/tests/display_source_code.rs
+++ b/crates/ra_hir_ty/src/tests/display_source_code.rs
@@ -29,7 +29,7 @@ fn omit_default_type_parameters() {
         //- /main.rs
         struct Foo<T = u8> { t: T }
         fn main() {
-            let foo = Foo { t: 5 };
+            let foo = Foo { t: 5u8 };
             foo<|>;
         }
         ",
@@ -41,7 +41,7 @@ fn omit_default_type_parameters() {
         //- /main.rs
         struct Foo<K, T = u8> { k: K, t: T }
         fn main() {
-            let foo = Foo { k: 400, t: 5 };
+            let foo = Foo { k: 400, t: 5u8 };
             foo<|>;
         }
         ",
diff --git a/crates/ra_hir_ty/src/tests/method_resolution.rs b/crates/ra_hir_ty/src/tests/method_resolution.rs
index 558a70022..804297315 100644
--- a/crates/ra_hir_ty/src/tests/method_resolution.rs
+++ b/crates/ra_hir_ty/src/tests/method_resolution.rs
@@ -184,60 +184,6 @@ fn test() {
 }
 
 #[test]
-fn infer_associated_method_generics_with_default_param() {
-    assert_snapshot!(
-        infer(r#"
-struct Gen<T=u32> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make() -> Gen<T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::make();
-}
-"#),
-        @r###"
-    80..104 '{     ...     }': Gen<T>
-    90..98 'loop { }': !
-    95..98 '{ }': ()
-    118..146 '{     ...e(); }': ()
-    128..129 'a': Gen<u32>
-    132..141 'Gen::make': fn make<u32>() -> Gen<u32>
-    132..143 'Gen::make()': Gen<u32>
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_generics_with_default_tuple_param() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct Gen<T=()> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make() -> Gen<T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::make();
-    a.val<|>;
-}
-"#,
-    );
-    assert_eq!(t, "()");
-}
-
-#[test]
 fn infer_associated_method_generics_without_args() {
     assert_snapshot!(
         infer(r#"
diff --git a/crates/ra_hir_ty/src/tests/simple.rs b/crates/ra_hir_ty/src/tests/simple.rs
index 88309157b..8a5031756 100644
--- a/crates/ra_hir_ty/src/tests/simple.rs
+++ b/crates/ra_hir_ty/src/tests/simple.rs
@@ -1997,3 +1997,111 @@ fn foo() {
     "###
     );
 }
+
+#[test]
+fn generic_default() {
+    assert_snapshot!(
+        infer(r#"
+struct Thing<T = ()> { t: T }
+enum OtherThing<T = ()> {
+    One { t: T },
+    Two(T),
+}
+
+fn test(t1: Thing, t2: OtherThing, t3: Thing<i32>, t4: OtherThing<i32>) {
+    t1.t;
+    t3.t;
+    match t2 {
+        OtherThing::One { t } => { t; },
+        OtherThing::Two(t) => { t; },
+    }
+    match t4 {
+        OtherThing::One { t } => { t; },
+        OtherThing::Two(t) => { t; },
+    }
+}
+"#),
+        @r###"
+    98..100 't1': Thing<()>
+    109..111 't2': OtherThing<()>
+    125..127 't3': Thing<i32>
+    141..143 't4': OtherThing<i32>
+    162..385 '{     ...   } }': ()
+    168..170 't1': Thing<()>
+    168..172 't1.t': ()
+    178..180 't3': Thing<i32>
+    178..182 't3.t': i32
+    188..283 'match ...     }': ()
+    194..196 't2': OtherThing<()>
+    207..228 'OtherT... { t }': OtherThing<()>
+    225..226 't': ()
+    232..238 '{ t; }': ()
+    234..235 't': ()
+    248..266 'OtherT...Two(t)': OtherThing<()>
+    264..265 't': ()
+    270..276 '{ t; }': ()
+    272..273 't': ()
+    288..383 'match ...     }': ()
+    294..296 't4': OtherThing<i32>
+    307..328 'OtherT... { t }': OtherThing<i32>
+    325..326 't': i32
+    332..338 '{ t; }': ()
+    334..335 't': i32
+    348..366 'OtherT...Two(t)': OtherThing<i32>
+    364..365 't': i32
+    370..376 '{ t; }': ()
+    372..373 't': i32
+    "###
+    );
+}
+
+#[test]
+fn generic_default_in_struct_literal() {
+    assert_snapshot!(
+        infer(r#"
+struct Thing<T = ()> { t: T }
+enum OtherThing<T = ()> {
+    One { t: T },
+    Two(T),
+}
+
+fn test() {
+    let x = Thing { t: loop {} };
+    let y = Thing { t: () };
+    let z = Thing { t: 1i32 };
+    if let Thing { t } = z {
+        t;
+    }
+
+    let a = OtherThing::One { t: 1i32 };
+    let b = OtherThing::Two(1i32);
+}
+"#),
+        @r###"
+    100..320 '{     ...32); }': ()
+    110..111 'x': Thing<!>
+    114..134 'Thing ...p {} }': Thing<!>
+    125..132 'loop {}': !
+    130..132 '{}': ()
+    144..145 'y': Thing<()>
+    148..163 'Thing { t: () }': Thing<()>
+    159..161 '()': ()
+    173..174 'z': Thing<i32>
+    177..194 'Thing ...1i32 }': Thing<i32>
+    188..192 '1i32': i32
+    200..241 'if let...     }': ()
+    207..218 'Thing { t }': Thing<i32>
+    215..216 't': i32
+    221..222 'z': Thing<i32>
+    223..241 '{     ...     }': ()
+    233..234 't': i32
+    251..252 'a': OtherThing<i32>
+    255..282 'OtherT...1i32 }': OtherThing<i32>
+    276..280 '1i32': i32
+    292..293 'b': OtherThing<i32>
+    296..311 'OtherThing::Two': Two<i32>(i32) -> OtherThing<i32>
+    296..317 'OtherT...(1i32)': OtherThing<i32>
+    312..316 '1i32': i32
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
index 0c538a62d..133fb5f39 100644
--- a/crates/ra_hir_ty/src/tests/traits.rs
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -1806,33 +1806,33 @@ fn test() {
 }
 "#),
         @r###"
-65..69 'self': &Self
-166..170 'self': Self
-172..176 'args': Args
-240..244 'self': &Foo
-255..257 '{}': ()
-335..336 'f': F
-355..357 '{}': ()
-444..690 '{     ...o(); }': ()
-454..459 'lazy1': Lazy<Foo, fn() -> T>
-476..485 'Lazy::new': fn new<Foo, fn() -> T>(fn() -> T) -> Lazy<Foo, fn() -> T>
-476..493 'Lazy::...| Foo)': Lazy<Foo, fn() -> T>
-486..492 '|| Foo': || -> T
-489..492 'Foo': Foo
-503..505 'r1': {unknown}
-508..513 'lazy1': Lazy<Foo, fn() -> T>
-508..519 'lazy1.foo()': {unknown}
-561..576 'make_foo_fn_ptr': fn() -> Foo
-592..603 'make_foo_fn': fn make_foo_fn() -> Foo
-613..618 'lazy2': Lazy<Foo, fn() -> T>
-635..644 'Lazy::new': fn new<Foo, fn() -> T>(fn() -> T) -> Lazy<Foo, fn() -> T>
-635..661 'Lazy::...n_ptr)': Lazy<Foo, fn() -> T>
-645..660 'make_foo_fn_ptr': fn() -> Foo
-671..673 'r2': {unknown}
-676..681 'lazy2': Lazy<Foo, fn() -> T>
-676..687 'lazy2.foo()': {unknown}
-550..552 '{}': ()
-"###
+    65..69 'self': &Self
+    166..170 'self': Self
+    172..176 'args': Args
+    240..244 'self': &Foo
+    255..257 '{}': ()
+    335..336 'f': F
+    355..357 '{}': ()
+    444..690 '{     ...o(); }': ()
+    454..459 'lazy1': Lazy<Foo, || -> Foo>
+    476..485 'Lazy::new': fn new<Foo, || -> Foo>(|| -> Foo) -> Lazy<Foo, || -> Foo>
+    476..493 'Lazy::...| Foo)': Lazy<Foo, || -> Foo>
+    486..492 '|| Foo': || -> Foo
+    489..492 'Foo': Foo
+    503..505 'r1': usize
+    508..513 'lazy1': Lazy<Foo, || -> Foo>
+    508..519 'lazy1.foo()': usize
+    561..576 'make_foo_fn_ptr': fn() -> Foo
+    592..603 'make_foo_fn': fn make_foo_fn() -> Foo
+    613..618 'lazy2': Lazy<Foo, fn() -> Foo>
+    635..644 'Lazy::new': fn new<Foo, fn() -> Foo>(fn() -> Foo) -> Lazy<Foo, fn() -> Foo>
+    635..661 'Lazy::...n_ptr)': Lazy<Foo, fn() -> Foo>
+    645..660 'make_foo_fn_ptr': fn() -> Foo
+    671..673 'r2': {unknown}
+    676..681 'lazy2': Lazy<Foo, fn() -> Foo>
+    676..687 'lazy2.foo()': {unknown}
+    550..552 '{}': ()
+    "###
     );
 }